chamberlin



J. CHAMBERLIN.

CONTROLLED LEVER FEED FOR MACHINE TOOLS.

' APPLICATION FILED was, 1918.

1 ,3 l 1 L947 Patented Aug. 5, 1919.

2 SHEETS-SHEET Fl G1.

[Tu (enter. film ha mberlim a torney.

J. CHAMBERLIN.

CONTROLLED LEVER FEED FOR MACHINE TOOLS. APPLICATION FILED Aue.5.19|x.'

1 ,3 1 1 ,947 Patented Aug. 5, 1919.

2 SHE ETSSHEET 2.

J'OI-IN CHAMBERLIN, OF LONDON, ENGLAND.

CONTROLLED LEVER-FEED FOR MACHINE-TOOLS.

Specification of Letters Patent.

Patented Aug. 5, 1919.

Application filed August 5, 1918. Serial No. 248,454.

T 0 all whom it may concern:

Be it known that I, JoIrN CHAMBERLIN, a subject of the King of Great Britain, residing at London, England, have invented certain new and useful Improvements in Controlled Lever-Feeds for Machine-Tools, of which the following is a specification.

The object of the present invention is to provide a controlled lever feed for drilling machines, capstan lathes, and the like by which an excessive rate of feed of the tool is resisted with the object of preventing or minimizing breakage of the tool by excessive feed, breakage usually also involving damage to the work and much loss of labor in removing the broken tool.

To this end a retarding device is provided which is so inter-related with the lever feed that the advance of the tool is effected against the action of the retarding device, the retardation being constant with a constant feed but varying in accordance with the increase or decrease of the rate of speed.

At the normal speed the retardation is ordinarily such as not to appreciably add to the resistance of the tool.

A furtherobject of the present invention is to enable the. tool at any stage of the feed to be withdrawn from the work for clearing without hindrance from the retarding means, and thereafter to prevent the resumption of the control of the lever feed until the tool again makes contact at the point up to which it had previously traveled.

In the hereinafter described preferred embodiment of the present invention the controlled lever feed comprises a hydraulic cylinder and piston which is so interrelated with the lever feed that advance of thedrill or other tool must be accompanied by a simultaneous movement of the piston against the resistance offered by the oil or other fluid within the cylinder being forced from one side of the piston to the other through a restricted passage which is preferably controlled by an adjustable valve.

In order that the piston shall not be actuated until the tool makes contact with the work, the operative connections between the lever feed andthe piston are made so as to allow the lever feed to bring the tool up to contact, or nearly up to contact, before the piston is actuated. Similarly, when withdrawing the tool, the lever feed is free to bring the tool clear of the work without imparting any reverse movement to the piston,

which remains stationary for resuming control when the tool is again advanced up to contact.

The invention is illustrated in the accompanying drawings which show two preferred constructions.

Figure 1 is a detail view of the lever feed of a vertical drilling machine, having the present invention applied.

Fig. 2 is a view showing the lever feedpf a horizontal drilling machine.

Figs. 8 and 4 are detail views of the operative connections.

Fig. 5 is a diagrammatic illustration of the adjustable piston valve.

In Figs. 1, 3 and 4 a convenient and advantageous mode of operatively connecting the lever feed of a vertical drilling machine with the retarding device or check, is shown the cylinder a being pivotally attached to the sliding bracket 7) of the machine slide 0. The piston rod (Z is linked to a bolt 0 which is screwed into the end of the drill feed boss 7 to form an axial extension of the boss. The link 9 is arranged to rotate freely on a bush h on the bolt, which bush serves to put clamping pressure on a pair of washers or disks 7? to clamp these to the boss 7 so as to rotate therewith, the clamping pressure being applied by the head of the bolt 0 when the bolt is tightened.

The washers have short radial arms 70 and In provided with side projections Z and Z to make contact with opposite sides of the link 9. By appropriate adjustment of the washers 2', the side projections l and Z are so set that. first, the projection Z which is to actuate the link 7 on the advance of the drill does not contact with the link until the drill is brought up to contact with the work or nearly so. Thereafter the-projection Z pushes the link 9 which in turn actuates the piston m. Secondly the projection Z on the other side of the link 9 is so set that the drill can be withdrawn out of the work sufficiently for clearing chips without the projection Z making contact with the link 9, thus leaving the piston m stationary, and enabling the drill to be readvanced at any speed back to the previous stage in advance at which the projection I will again make contact with the link g, and bring the control again into action. When however the feed lever n is returned to starting or ofl position, the projection Z gives that range of movement to the link which copies of tliis'patent may be obtained for five cents each, b y,ad dressingthe Commissioner of Patents,

shall in turn bring the piston we back to its original position. On this return stroke of the piston the fluid is allowed by a suitable valve 0 to pass freely through the piston m.

An alternative method particularly suited for a capstan lathe or horizontal drilling machines is shown in Fig. 2 and'cornprises a pivoted sleeve 19 fixed intermediately of the ends of the hand operating lever a, through which sleeve is passed the free end of the piston rod d, suitably extended in length. On the piston rod cl, and on opposite sides of the sleeve p, are adjustable stops Z which are set to allow the feed lever to have movement independently of the control and to-connect it with the control as hereinbefore described.

As shown in Fig. 5, the flow of fluid through the piston m may be controlled as desired by causing the apertures 0 in the valve 0 to register more or less withthe openings m in the piston m, the adjustment beingefiectedby slackening the nut?" on the end of the piston rod d.

While I have described, in the foregoing specification the construction of parts and operations prefer-red, I am aware that numerous changes of construction and operation may. bemade withoutdeparting from thespirit and scope of the invention, and I, therefore, do not wish to be understood as limitingrmyself by the positive terms employed in connection with the description eX- cept such as the state of theart vmay require.

1. A controlled lever feed for machine tools comprising in combination a feed-lever, a retarding device, connecting means therebetween, means operated by the feed lever to actuate said retarding device, and setting means for controlling theactuation of the retardingdevice whereby the said retarding device .does not become operative .until the tool has been brought into or nearly into contact with the worlqfor the purpose described;

2. A controlled lever feed for machine tools comprising in combination a feed lever, a retarding device, connecting means therebetween, means operated by the feed lever to actuate said retarding device, and setting means for controlling the actuation of the 'retardingdevice, whereby the said retarding device 1s not operative during partial withdrawal of the tool for the purpose described.

3. A controlled lever feed for machine tools comprising in combination a feed lever, a movable member, a hydraulic cylinder, a

piston therein, a valve control, a connection able member, and setting means intermedi-.

ate .of the feed lever and hydraulic cylinder,

said movable member being adapted to be coupled to the feed lever for movement through said setting means, substantially as and for the purposes described.

5., A controlled lever feed for machine tools comprising in combination a feed lever, a movable member, a hydraulic cylinder, a piston therein, a regulated valve in said pis ton, a connection between said. piston and said movable member, and settingmeans intermediate of the feed lever and hydraulic cylinder,said movablemember being adapted to be coupled to the feed lever for movement through said settingmeans, substantially as and for the purposes described;

In testimony whereof, I afiix my. signature. r

JOHN OHAMBERLIN Washington, D. C. 

